JP2005042110A - Coating, its manufacturing method, its use, and coated product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating suitable for a metal packaging composed of a tin plate, aluminium and TFS (tin free steel). <P>SOLUTION: A solvent-containing coating is composed of a saturated copolyester containing at least one hydroxy group, a phenol-formaldehyde-resin, benzoguanamine-formaldehyde-resin and/or a blocked polyisocyanate, a catalyst and a solvent, and optionally an adjuvant and an additive. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The invention relates to a solvent comprising a saturated copolyester containing at least one hydroxy group, a phenol-formaldehyde resin, a benzoguanamine-formaldehyde resin and / or a blocked polyisocyanate, a catalyst, a solvent and optionally auxiliaries and additives. Containing paint.

  This coating is used for external and internal application of metal packaging products, where the coating is polyvinyl chloride (PVC), bisphenol A (BPA) and bisphenol-A-diglycidyl-ether (BADGE), bisphenol-F- Does not contain diglycidyl-ether (BFDGE), novolac-glycidyl-ether (NOGE) and derivatives thereof. This paint is suitable for roll application of metal plates or metal bands, especially for strongly molded metal packaging with excellent adhesion and sterilization stability in acidic media such as especially acetic acid and lactic acid.

  Metal packaging products for food and beverages, such as cans, tubes and closures, usually have organic paint (“Canmaking, The Technology of Metal Protection and Decoration” TA Turner, Blackie Academic & Professional, London, 1998 , p 82; “Polymeric Materials Science and Engineering”, Vol. 65, fall meeting 1991 New York, p277-278), which on the one hand protects the metal from rust, achieves processing and on the other hand protects the filling material, Thus, the food contents are retained. Furthermore, the color, structure and taste of the filling material must not change over the period that the metal package product is maintained. Therefore, metal migration into the filler material should also be prevented by the organic coating. Furthermore, the filling material must not be affected or altered by the coating itself and by the elution part of the coating ("Verpackung von Lebensmitteln" Rudolf Heiss, Springer Verlag, Berlin 1980, p 234ff).

  Paint is applied in a roll application process, continuously in so-called coil lines (Coil-Linien) or discontinuously in so-called plate application lines (Tafellacker-Linien), with thin metals such as aluminum, tinplate or chromated steel (THS = tin free steel) and continue to react at high temperature.

  The coated metal thus produced is subsequently formed into a desired metal package product by a method such as deep drawing, punching, embossing and blow molding. This mechanical operation requires very high flexibility and excellent adhesion of the paint used. This does not cause a change in the protective function by the molding process and must still have a problem-free adhesion and a perfect surface.

  The metal packaged product is subjected to a process for making it possible to store for a long time after filling with foodstuffs. This is for example pasteurization or sterilization; likewise, this heat treatment does not allow the paint to change at all in terms of protective function, adhesion and surface. Today, paints based on epoxy-phenol-paints, so-called “Gold-Lacken”, are used, especially for direct food contact (“Ullmann's Encycropedia of Industrial Chemistry”, Vol. A18). , VCH Verlagsgesellschaft, Weinheim 1991, p527).

  This paint has good adhesion and is particularly suitable for aggressive filling materials, especially acidic filling materials. When particularly high demands are made on the flexibility of the paints, PVC-dispersions, so-called organosols, are often used which have very good adhesion and good deep drawing properties (Tiefzieheigenschaft).

  However, both epoxy-phenol-paints and organosols are BADGE [bisphenol-A-diglycidyl-ether (2,2′-bis (4-hydroxyphenyl) propane-bis (2,3-epoxypropyl) ether)] and / or BPA. [Bisphenol-A = (2,2′-bis (4-hydroxyphenyl) propane)]. In addition, BFDGE and NOGE are also used. The PVC-organosol additionally contains PVC.

  Today, from the food packaging industry and consumer groups, the coatings on the one hand do not contain any epoxy compounds (BADGE, BFDGE, NOGE and their derivatives), bisphenol A and PVC and their derivatives, on the other hand, conventionally used organic coatings. There is a need for a metal packaged product coated with a paint having comparable properties.

  Bisphenol A is suspected of having a hormone-like action in human organs, and therefore there is a need to avoid ("Bisphenol A, A Known Endocrine Disruptor" WWF European Toxis Program Report, April 2000, p11). The use of BADGE and BFDGE with their respective limits is regulated in Europe by the Commission Directive 2002/16 / EC (see also Councill Directive 89/109 / EEC, Directive 90/128 / EEC). The use of NOGE has been banned since the beginning of 2003 for coatings that come into direct contact with food.

  Polyesters are generally suitable for external application of metal packaging products in the context of crosslinking components such as melamine resins, benzoguanamine resins or blocked polyisocyanates. This is flexible and can be sterilized in water without problems and is thus a known technique. (Protective Coatings, Clive H. Hare, Technology Publishing Company, Pittsburgh, USA, 1994, p149; Tinplate and Modern Canmaking Technology, E. Morgan, Pergamon Press, Oxford, p195ff; Can making, The technology of metal protection and decoration, TA Turner, Blackie Academie Professional, London 1998, p 40ff).

  When a polyester-benzoguanamine paint colored with titanium dioxide is used for the interior coating of cans, only high molecular weight polyesters (Mn> 12000) provide sufficient sterilization stability in acidic filling materials.

  US Pat. No. 6,472,480 describes combinations of polyesters with phenoxy group-containing resins or amino group-containing resins; all polyesters suitable for the purpose of use must contain naphthalene dicarboxylic acid and are trifunctional monomers For example, it must show a branched structure by using TMA or TMP. The nature of this paint appears to be particularly problematic with respect to sterilization in acidic media.

  DE 1991 2794 (Grace) describes BADGE-free can coatings, but contains bisphenol A as a component (see Table V, comparative example B, polyester 5).

  Kansai Paint similarly describes polyester phenol coatings containing bisphenol A (JP200220141, JP2001113147, JP11315251).

  GB 349464 (ICI) describes the use of “Glyptalharzen” (polyester consisting of glycerin and phthalic anhydride) in combination with phenol-formaldehyde-resole and urea-formaldehyde-resin in an aqueous emulsion. This paint is not suitable for the intended use "metal packaging application".

  The polyester-phenoplast coating described in GB 1190991 (Schenectady) is for electrical insulating paints (wire paints).

  The thermosetting coating described in DE 2228288 (Stolllack) is a phenol-aldehyde resin coating that avoids the sulfonation phenomenon. When the proportion of phenol-formaldehyde resin is varied between at least 50% and 95% and the proportion of phenol is reduced to 30%, the resulting paint becomes sticky. The binder used is of the alkyd type, i.e. oil-containing polyester, and is used at 10-30%. The adhesion of this coating after mechanical shaping and sterilization is not described and is questionable.

  DE 401 0167 (BASF) describes a method for the internal coating of metal plate packaging. As the paint, carboxy group-containing polyester and phenol resin are described. The disadvantage of this invention is the use of one or more epoxy resins to improve adhesion as well as the use of thermoplastic resins.

  WO 95/23198 (DSM) describes the use of hydroxy group-containing polyesters for the inner coating of cans. The disadvantage of this described polyester is that it must have a glass transition temperature of at least 40 ° C., and in particular uses an epoxy resin as a crosslinking component.

  The polyester-phenol-formaldehyde combination exhibits so-called microcracking after molding, for example, can corner or impact bend specimen microcracking. This microcrack is a defect location in the coating, where the protective function of the coating is damaged and is therefore not suitable for use as an internal protective film for metal packaging (Example 8, Table IX, Paint C reference).

  JP 2002226343A describes the use of a branched copolyester for coating the inside of a can. There is no description of the crosslinking agents used, suggesting major concepts such as aminoplasts, phenolic resins, melamine resins, multifunctional isocyanates, blocked isocyanates and multifunctional aziridine resins which are listed as polyester crosslinking agents: This represents only general knowledge for the crosslinking reaction of polyesters (see Lackharze; D. Stoye, W. Freitag; p 47; Carl Hanser Verlag, Muenchen 1996).

None of the patents describe the use of hydroxy group-containing saturated copolyesters in combination with phenol-formamide resins, benzoguanamine resins and / or blocked polyisocyanates.
USP6472480 DE19912794 JP200220141 JP200113147 JP11315251 GB349464 GB1119091 DE2228288 DE4010167 WO95 / 23198 JP2002302643A “Canmaking, The Technology of Metal Protection and Decoration” TA Turner, Blackie Academic & Professional, London, 1998, p 82 “Polymeric Materials Science and Engineering”, Vol. 65, fall meeting 1991 New York, p277-278 “Verpackung von Lebensmitteln” Rudolf Heiss, Springer Verlag, Berlin 1980, p 234ff “Ullmann's Encycropedia of Industrial Chemistry”, Vol. A18, VCH Verlagsgesellschaft, Weinheim 1991, p527 “Bisphenol A, A Known Endocrine Disruptor” WWF European Toxis Program Report, April 2000, p11 Protective Coatings, Clive H. Hare, Technology Publishing Company, Pittsburgh, USA, 1994, p149 Tinplate and Modern Canmaking Technology, E. Morgan, Pergamon Press, Oxford, p195ff Can making, The technology of metal protection and decoration, TA Turner, Blackie Academie Professional, London 1998, p 40ff Lackharze; D. Stoye, W. Freitag; p 47; Carl Hanser Verlag, Muenchen 1996

  The challenge is to find a suitable paint for metal packaging consisting of tin, aluminum and TFS. The paint should be free of bisphenol-A, bisphenol-A-diglycidyl-ether, bisphenol-F-diglycidyl-ether, novolac-glycidyl-ether and derivatives thereof as well as PVC and its derivatives. This paint consists of three parts and is suitable for the inner and outer coating of deep-drawn metal packaging, especially it can replace the conventionally used inner protective paint made of epoxy-phenol-resin It should also be suitable with regard to (impact bending test, can with 4 corners) and chemical stability (MEK-stability, sterilization).

The subject of the present invention is essentially A) 55-75% by weight of at least one hydroxy group-containing polyester, and B) 5-13% by weight of phenol-formaldehyde resin, and C) 0-12% by weight of benzoguanamine-formaldehyde resin. And / or D) blocked polyisocyanate 0-10% by weight, and E) catalyst 0.5-2% by weight, and F) at least one solvent 5-30% by weight.
In this case, the total mass described for the components A) to F) is 100% by mass and contains at least components C) and / or D).

  It has been found that the combinations of hydroxy group-containing saturated copolyesters described below with phenol-formaldehyde-resins, benzoguanamine-formaldehyde-resins and / or blocked polyisocyanates meet all necessary criteria.

  The copolyesters used are in particular permitted by direct food contact according to “§ 175300 FDA” (die amerikanische Food and Drug Administration) and / or European regulations “2002/72 / EG” (established 90/128 / EG). Only based on the raw materials.

  The polyester used can be used without using naphthalene dicarboxylic acid (see Polyesters 1 to 4), and it has also been found that polyesters having no branched structure are suitable (Polyesters 2, 3, 4). reference).

  Surprisingly, medium molecular weight copolyesters exhibit high chemical stability after sterilization with acetic acid and lactic acid.

  Molded metal coatings exhibit significantly better sterilization stability, especially in acidic media such as acetic acid and lactic acid, without loss of adhesion.

  In particular, this coating does not show any microcracking after mechanical forming.

Polyester A)
Polyester A according to the present invention is produced by condensation according to known methods (disclosed and referred to by Dr. P. Oldring, Resins for Surface Coatings, Volume III, Sita Technology, 203 Gardiness House, Broomhill Road, London SW 184JQ, England 1987). . The polyester used consists of a di- and / or polycarboxylic acid mixture and a di- or polyol mixture. This is contained in the paint at 55 to 75% by weight, preferably 56 to 73% by weight.

  In particular, customary carboxylic acids and their esterifiable derivatives, such as phthalic acid, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, succinic acid, sebacic acid, methyltetra-, methylhexahydrophthalic acid, Tetrahydrophthalic acid, dodecanedioic acid, adipic acid, azelaic acid, naphthalene dicarboxylic acid, pyromellitic acid, dimer fatty acid and / or trimellitic acid, acid anhydrides and / or lower alkyl esters thereof such as methyl esters can be used.

  Preference is given to using isophthalic acid, terephthalic acid, adipic acid, sebacic acid, dimer fatty acids, trimellitic acid, their anhydrides and / or esterifiable derivatives.

  Examples of the alcohol component include ethylene glycol, 1,2- and / or 1,3-propanediol, diethylene-, dipropylene-, triethylene-, tetraethylene glycol, 1,4-butanediol, 1,3-butyl. Ethylpropanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, cyclohexanedimethanol, glycerin, 1,6-hexanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, 1,4 Use of benzyldimethanol and -ethanol, 2,4-dimethyl-2-ethylhexane-1,3-diol and / or dicidol, preferably 1,3-methylpropanediol, NPG, ethylene glycol, trimethylol Use propane. In particular, this monomer should be able to meet “§175300 FDA” and / or European regulations “2002/72 / EG”.

This copolyester
a. Acid number 0-10 mg KOH / g, preferably 0-5 mg KOH / g, in particular 0-3 mg KOH / g,
b. Hydroxy value of 3-80 mg KOH / g, preferably 10-50 mg KOH / g, in particular 15-30 mg KOH / g,
c. Glass transition temperature (Tg) -20 ° C to + 50 ° C, preferably -10 ° C to + 40 ° C,
d. Linear or branched structures, preferably linear or slightly branched, particularly preferably linear structures,
e. Molecular weight (Mn) 2000-20000
It is characterized by.

Phenol-formaldehyde resin B)
Phenol-formaldehyde resin B) is used in an amount of 5 to 13% by weight, preferably 6 to 12% by weight. Preference is given to using phenolic resins of the resol type, for example phenolic, butylphenol, xylenol- and cresol-formaldehyde types, in particular etherified with butanol (for phenolic resin chemistry, production and use). (See "The Chemistry and Application of Phenolic Resins or Phenoplasts", Volume V, Part I, edited by Dr. Oldring; John Wiley and Sons / Sita Technology Ltd, London, 1997).

Phenolic resins used are, for ^{example: PHENODUR (R) PR 285 (} 55%), PR 612 (80%), Voianova Resins, Mainz-Kastel, BAKELITE (R) 6581LB ( etherified cresol resol in n- butanol), Bakelite , Iserlohn-Lemathe.

Benzoguanamine-formaldehyde-resin C)
Benzoguanamine-formaldehyde-resin C) is used in an amount of 0 to 12% by weight, preferably 2 to 10% by weight. Preference is given to using fully etherified, in particular butanol- or mixed methanol / ethanol-etherified, benzoguanamine-formaldehyde resins (2,4-diamino-6-phenyl-1,3,5-triazine). Yes (for chemistry, production and use “The Chemistry and Application of Amino Crosslinking Agents or Aminoplasts”, Volume V, Part II, p 21ff., Edited by Dr. Oldring; John Wiley and Sons / Sita Technology Ltd, London , 1998). Which can be used is in particular the following commercially available ^{benzoguanamine: MAPRENAL (R) MF 980 (} 55% in n- butanol), 988 (80% in n- butanol), Vianova Resins, Mainz-Kastel ; CYMEL ( ^R) 1123 (98%), Cytec, Neuss; LUWIPAL B017 (85% in isobutanol) BASF, Ludwigshafen.

Blocked polyisocyanate D)
Preference is given to using aliphatic and / or alicyclic blocked polyisocyanates, such as HDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), H ₁₂ MDI and their trimers. In particular, polyisocyanates produced with the following blocking agents were used:
n- butanone oxime, .epsilon.-caprolactam, secondary amines, for example ^VESTANAT (R) B1358A ^(63% in SN100), VESTANAT (R) EP B1186A (60% in SN100), VESTANAT (R) EP B1299SV (SN100 in 53% ), Degussa, Marl; DESMODUR BL3175 (75% in SN100) Bayer, Leverkusen. The blocked polyisocyanate is contained in the paint according to the invention in an amount of 0 to 10% by weight, preferably in an amount of 5 to 9% by weight.

  In the present invention, the component C) or D) may be contained alone or together in the coating material according to the present invention, and in particular, 5 to 10% by mass in the case of C) alone, and 6 in the case of D) alone. In the case of ˜9% by weight and C) + D), the amount of C: 2-5% by weight and the amount of D: 5-8% by weight are advantageous.

Catalyst E)
In general, acidic catalysts can be used, especially those listed in Table I, such as phosphoric acid solutions, phosphoric acid ester solutions, such as ADDITOL® XK406 ⁽ derivatives of phosphoric acid), Voianova Resins, Mainz-Kastel A phosphoric acid solution (85% phosphoric acid 1: 1 in butyl glycol) is preferred. In general, tin catalysts can be used, preferably dibutyltin dilaurate (= DBTL) in Tables II and III, such as METATIN 712, Acima, Buchs, Schweiz.

Solvent F)
Solvents that can be used include: aromatic hydrocarbons (eg, solvent naphtha 150,200) glycol ethers and glycol esters (eg, butyl glycol (= BG), methoxypropanol (= MP), butyl glycol acetate (= BGA), methoxypropyl acetate (= MPA)).

  Auxiliaries and additives may additionally be included. For example, lubricant (polyethylene wax, PTEF-wax, carnauba wax), filler (titanium dioxide, zinc oxide, aluminum), matting agent (precipitated silicic acid), wetting and dispersing agent, antifoaming agent (modified siloxane) Can be contained.

Paint production:
The paint is produced by vigorously stirring the ingredients at a temperature of 20-80 ° C. (“Lehrbuch der Lacktechnologie”, Th. Brock, M. Groteklaes, P. Mischke, Hrsg. V. Zorll, Vincentz Verlag, Hannover, 1998, p229ff). Prior to mixing, the non-liquid components are first placed in a suitable solvent to form a solution and then all remaining components are fed under stirring.

  This paint exhibits high solvent stability, for example up to 100 Doppelhueben in methyl-ethyl-ketone (MEK). The paints according to the invention are very flexible and adherent, which is revealed by slight damage (damage 0-13 mm) in the impact-bending test.

  The paint according to the invention is used for the application on the inside and outside of three-part and deep-drawn metal packaging products such as cans, lids and closures. The applied metal can be formed mechanically, for example by deep-drawing, embossing or extrusion, followed by sterilization, especially in acetic acid and lactic acid, with loss of adhesion. Is not seen. A can with four corners is thus stamped and formed into corners with a radius of curvature of 5, 10, 15 and 20 mm and a small bowl shape with stretch ratios of diameter to height of 1: 0.75 and 1: 1.3. Although it is stretched, no adhesion loss occurs.

  The paint exhibits a satisfactory flow on the metal substrate used and does not have surface defects such as craters and cross-linking defects.

  The paint has a solids content of 35 to 45%, preferably 37 to 42%, with an Auslaufviscositaet DIN 4 mm (20 ° C.) of 95 to 110 seconds.

  The invention will now be described in detail by way of example.

(The percentage numbers listed in the table are normalized to 100)
Polyester examples for Tables I, I / A, II, II / A, II / B and III:
The mol% of the carboxylic acid component and the alcohol component are separately standardized to 100 mol%. The polyester is dissolved in the solvent naphtha 150 / butyl glycol (4/1).

Polyester 1
Composition 55% solution: terephthalic acid 40%, isophthalic acid 30%, sebacic acid 30% // neopentyl glycol 37%, methylpropanediol 60%, trimethylolpropane 3%.
Viscosity: 4.0 Pa · s, acid value: 0.2 mgKOH / g, hydroxy value: 25 mgKOH / g, glass transition temperature: 0 ° C., molecular weight (theoretical value) 5800.

Polyester 2
Composition 55% solution: terephthalic acid 30, isophthalic acid 40, sebacic acid 30 // neopentyl glycol 100, viscosity: 1.6 Pa · s, acid value: 1.3 mgKOH / g, hydroxy value: 21 mgKOH / g, glass transition temperature : 7 ° C., molecular weight (theoretical value) 5800.

Polyester 3
Composition 55% solution: terephthalic acid 50, isophthalic acid 20, sebacic acid 30 // methyl-propanediol 100, viscosity: 2.5 Pa · s, acid value: 0.7 mgKOH / g, hydroxy value: 22 mgKOH / g, glass transition Temperature: -9 ° C, molecular weight (theoretical value) 5800.

Polyester 4
30% solution in composition solvent naphtha 150: terephthalic acid 30, isophthalic acid 63, dimer fatty acid 7 // neopentyl glycol 52, ethylene glycol 48, viscosity: 0.6 Pa · s, acid value: 0.9 mgKOH / g, hydroxy Value: 5 mg KOH / g, glass transition temperature: 40 ° C., molecular weight (theoretical value) 15000.

Polyester 5 (Comparative) Polyester examples for Table V:
(Polyester post-treatment is described in Patent Grace DE 19912794)
Composition polyester 5, 50% polyester in solvent naphtha / BG (4/1): terephthalic acid 26.1, isophthalic acid 34.6, adipic acid 39.3 // neopentyl glycol 51.1, ethylene glycol 43.0 , Trimethylenepropane 5.9, viscosity: 2.7 Pa · s, acid value: 4 mgKOH / g, hydroxy value: 34 mgKOH / g.

Paint Composition Paint I: Polyester, phenolic resin, benzoguanamine, catalyst, solvent from Example 1

  Paint II: polyester from Example 2, phenolic resin, blocked polyisocyanate, catalyst, solvent

  Paint II / 1: Polyester, phenolic resin, blocked polyisocyanate, catalyst, solvent from Examples 3 and 4

  Paint III: Polyester from Example 2; phenolic resin, benzoguanamine, blocked polyisocyanate, catalyst, solvent

Comparative Example A
Paint A: Epoxy resin, phenol resin, catalyst, solvent

Crosslinking ratio: epoxy resin (solid resin): phenol-formaldehyde resin (solid resin) = 75: 25
Epikote 1009 (Shell, Eschborn), Phenodur PR897 (Vianova Resins, Mainz-Kastel)
Comparative Example B
Paint B: Polyester 5, phenolic resin, catalyst, solvent (polyester similar to Example 1 from DE 19919274)

Comparative Example C
Paint C: Polyester 1 or 2 or 3, phenol resin, catalyst, solvent

Abbreviated form: MPA = methoxypropyl acetate, BG = butyl glycol, BGA = butyl glycol acetate Coating evaluation Coating is applied on tinplate at about 5-7 g / m ² (dry film mass), and temperature 205 commonly used for can coating Bake at 13 ° C. (pmk = peak metal tenperatur) for 13 minutes (residence time in the furnace). One of ordinary skill in the art who tested the cross-linking for integrity using methyl ethyl ketone (MEK) is also commonly used as the concept “MEK-DoppelHuebe”. The test for the flexibility of the coating carries out the so-called “Schlagfalt-Test” known to those skilled in the art. The other test involves stamping the coated tinplate into a can with four corners. The can is sterilized in water, 3% acetic acid and 2% lactic acid at 129 ° C. for 30 minutes. After completion of sterilization, this coating is evaluated for adhesion and surface quality at four different corners. "Weissbruch" was evaluated, particularly in impact bending tests and cans with 4 corners.

ａ．１ｋｐ質量のダブルストロークの数
ｂ．損傷を受けた被覆（ｍｍ）
ｃ．曲率半径５／１０／１５／２０を有する４つの角：１＝付着損失なし、２＝付着損失２５％、３＝付着損失５０％、４＝付着損失７５％、０＝完全な剥離。
ｄ．滅菌後、ｃと同様に評価、
ｅ．表面の粗さ＊＝僅かに粗面化、
ｆ．１（水吸収なし）〜５（強い水吸収）の視覚的観点
ｇ．好適でないので、試験せず
本発明による塗料に対する比較としての比較例６、塗料Ｂ（表ＶＩＩＩ）は、この使用目的のために塗料Ｂが好適でないことを明らかに示している、それというのも衝撃曲げ試験（欠損４０ｍｍ）も４つの角を有する缶（曲率半径５および１０ｍｍの角隅はすでに滅菌の前に５０％まで障害を有する）も明らかに機械的な障害を有する。酸性媒体中での滅菌の後、付着は完全になくなる。

a. Number of double strokes of 1 kp mass b. Damaged coating (mm)
c. Four corners with radius of curvature 5/10/15/20: 1 = no adhesion loss, 2 = adhesion loss 25%, 3 = adhesion loss 50%, 4 = adhesion loss 75%, 0 = complete debonding
d. After sterilization, evaluation as in c,
e. Surface roughness * = slightly roughened,
f. Visual viewpoint of 1 (no water absorption) to 5 (strong water absorption) g. Not tested, not tested Comparative Example 6, Paint B (Table VIII) as a comparison to the paint according to the invention clearly shows that Paint B is not suitable for this purpose of use, since The impact bend test (defect 40 mm) and cans with 4 corners (corner corners with curvature radii of 5 and 10 mm already have up to 50% failure before sterilization) also clearly have mechanical failure. After sterilization in an acidic medium, adhesion is completely eliminated.

  Regarding Comparative Example 8 (Table IX), it is shown that a suitable paint cannot be obtained in the case of cross-linking only with a phenol resin.

  Comparative Example 5 (Table VIII, epoxy phenol) shows good chemical stability after sterilization in acidic media and is suitable for at least the coating of metal packaging products to be achieved by selective paints that do not use epoxy resin. The current level.

  The paint examples 1, 2, 3 and 4 (without using epoxy and bisphenol A) according to the invention clearly show a flexibility (impact bending test, can with 4 corners) compared to 5 in the comparative example It is excellent and has the same degree of adhesion and flexibility after sterilization.

Claims (24)

Substantially A) 55-75% by weight of at least one hydroxy group-containing polyester, and B) 5-13% by weight of phenol-formaldehyde resin, and C) 0-12% by weight of benzoguanamine-formaldehyde resin, and / or D). Blocked polyisocyanate 0-10% by weight, and E) catalyst 0.5-2% by weight, and F) at least one solvent 5-30% by weight
In this case, the total of the described masses of components A) to F) is 100% by mass and contains at least components C) and / or D).   The polyester used as component A) is phthalic acid, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, succinic acid, sebacic acid, methyltetra-, methylhexahydrophthalic acid, tetrahydrophthalic acid, dodecanedioic acid, adipine The paint according to claim 1, comprising a carboxylic acid selected from acids, azelaic acid, naphthalene dicarboxylic acid, pyromellitic acid, dimer fatty acid and / or trimellitic acid, acid anhydrides and / or esterified derivatives thereof.   The polyester used as component A) is ethylene glycol, 1,2- and / or 1,3-propanediol, diethylene-, dipropylene-, triethylene-, tetraethylene glycol, 1,4-butanediol, 1, 3-butylethylpropanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, cyclohexanedimethanol, glycerol, 1,6-hexanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, The paint according to claim 1 or 2, which contains an alcohol component selected from 1,4-benzyldimethanol and -ethanol, 2,4-dimethyl-2-ethylhexane-1,3-diol and / or dicidol.   The polyester used as component A) exhibits an acid value of 0-10 mg KOH / g, a hydroxy value of 3-80 mg KOH / g, a glass transition temperature of -20 to + 50 ° C. and a molecular weight (Mn) of 2000 to 20000. The paint according to any one of the above.   5. A paint according to claim 1, comprising as component B) a resol type phenolic resin, preferably an etherified xylenol- or cresolphenol-formaldehyde resin.   6. A paint as claimed in claim 1, wherein the polyester A) exhibits an acid value of 0 to 10 mg KOH / g, preferably 0 to 5 mg KOH / g, in particular 0 to 3 mg KOH / g.   7. The paint according to claim 1, wherein the polyester A) exhibits a hydroxy value of 3 to 80 mg KOH / g, preferably 10 to 50 mg KOH / g, in particular 15 to 30 mg KOH / g.   8. A paint according to claim 1, wherein the polyester A) has a glass transition temperature (Tg) of -20 [deg.] C. to +50 [deg.] C., preferably -10 [deg.] C. to +40 [deg.] C.   9. The polyester A) according to claim 1, wherein the polyester A) has a linear or branched structure, preferably a linear or slightly branched structure, particularly preferably a linear structure. The paint according to item 1.   The paint according to any one of claims 1 to 9, wherein the polyester A) has a molecular weight (Mn) of 2000 to 20000.   11. A paint according to claim 1, comprising as component C) benzoguanamine-formaldehyde, in particular benzoguanamine fully etherified with butanol or methyl / ethyl.   The paint according to any one of claims 1 to 11, which contains an aliphatic and / or alicyclic blocked polyisocyanate as component D). HDI and / or IPDI or _H 12 MDI and containing a polyisocyanate based, according to claim 7, wherein the coating composition.   14. The paint according to any one of claims 1 to 13, which contains an acid or an organometallic compound as component E).   The paint according to any one of claims 1 to 14, comprising phosphoric acid, a phosphoric acid derivative or a tin catalyst.   16. The paint according to claim 1, wherein the component F) contains an aromatic hydrocarbon, glycol ether and / or glycol ester.   The paint according to any one of claims 1 to 16, comprising an auxiliary and an additive. Substantially A) 55-75% by weight of at least one hydroxy group-containing polyester, and B) 5-13% by weight of phenol-formaldehyde resin, and C) 0-12% by weight of benzoguanamine-formaldehyde resin, and / or D). Blocked polyisocyanate 0-10% by weight, and E) catalyst 0.5-2% by weight, and F) at least one solvent 5-30% by weight
In the manufacturing method of the coating material containing this, these components are mixed strongly at the temperature +20 degreeC-+80 degreeC, The manufacturing method of the coating material characterized by the above-mentioned.   Use of a paint according to any one of claims 1 to 17 for applying metal bands and plates.   Use of a paint according to any one of claims 1 to 15 for external and internal application of metal packaging products.   18. Use of a paint according to any one of claims 1 to 17 for producing a metal packaging product which is mechanically formed, for example by deep drawing, blow molding, stamping and embossing.   A metal coated product made of the paint according to any one of claims 1 to 17.   The coated product according to claim 22, which is a packaged product.   24. The coated product of claim 23, wherein the coated product is a can, closure member, tube or film.